Pope Benedict XVI asked for forgiveness Friday from God and victims of pedophile priests and said he would do everything possible to ensure that minors will never again be molested by priests.‬‪

The appeal came in the closing ceremony of the Vatican's Year of the Priest.‬‪

"We, too, insistently beg forgiveness from God and from the persons‬‪ involved, while promising to do everything possible to ensure that such abuse will never occur again," Benedict said.

But the statement did not satisfy many victims, who are demanding accountability, said ‬‪‬‪Joelle Casteix, spokesperson for the main U.S. clerical abuse victims group, Survivors Network for Those Abused by Priests.

"Unless he says this is exactly what I am going to do, and this is exactly how I'm going to involve law enforcement, and this is my responsibility in the matter, it is little more than words, and we need concrete action," Casteix said.

Benedict made his comments in St. Peter's Square, a sea of white on Friday with as many as 15,000 priests in floor-length robes sitting silently under glaring sunshine during the closing Mass.

In his long speech, Benedict spoke of the uniqueness of the role of the priesthood in the Catholic Church.‬‪

But he also said that in this year of joy, "the sins of priests came to light -- particularly the abuse of little ones."‬‪‬‪ Benedict said that from now on, the Roman Catholic Church will do everything it can to screen men seeking to join the priesthood to determine the authenticity of their vocation.‬‪‬‪ The pledges were similar to ones he reportedly made in a private encounter with abuse victims in Malta in April.‬‪

And the tone of his remarks echoed what he said on a flight to Portugal in May when he acknowledged that the church is being persecuted not from the outside, but from sins within.

Following those statements, some Vatican-watchers had predicted that the pope, at Friday's ceremony, would address the worldwide sex abuse scandal and announce a major new policy.‬‪

Instead, he said the crisis is a summons to purification.‬‪ The statement fell short of many victims' hopes. ‬‪

"We find if very, very disappointing," Casteix said. "While it is important to focus on formation of new priests, it is far more important to keep kids safe now by instituting zero tolerance to make sure any man who has hurt a child or any man who has covered up for someone who has hurt a child is immediately removed from priesthood and handed over to secular authorities."

Friday's Mass was preceded by a vigil service Thursday night in St. Peter's Square in which the pope responded to pre-selected questions from five priests.‬‪ In one query, Benedict was asked about "the beauty of celibacy."

Benedict called celibacy a great sign of faith and said it represents an act of transcendence that brings the priest closer to God.‬‪‬‪ The Catholic Church has denied that celibacy is one of the causes of child abuse in the priesthood -- but even some leading cardinals have begun to question the requirement and are urging an open debate on the topic.‬‪

But the Vatican discouraged reporters from seeking the views of some of the thousands of priests who came to Rome -- the Holy See police prevented even Vatican-accredited reporters from interviewing priests in St. Peter's Square.‬

One priest who was willing to speak on the sidelines of the ceremony was the Rev. Jose Vasco of Mozambique.‬‪

"The church first tried to resolve the cases on its own," Vasco said. "But now that they have become so grave, the church must seek the full truth, and to do that we need joint commissions with lay people, with civil society, especially at a time when there is the appearance that the church has protected the guilty ones."

Vasco said he would welcome the idea of a debate on celibacy to determine whether it could be one of the causes of the sex abuse crisis and if it should be mandatory.